Sony joins a number of music streaming services today with its launch of "Music Unlimited powered by Qriocity." The service has been available in parts of Europe since last year, and arrives in the U.S., Australia, and New Zealand today.

Membership will start at $3.99 a month, with a $9.99 per month subscription that will give you on-demand access to the Music Unlimited catalog and with the ability to suggest music you might like based on the songs you already own or listen to. The service boasts more than 6 million songs, giving Sony Music Entertainment and its partners in the endeavor - Universal Music Group, EMI Music and Warner Music Group Corp - the ability to sell directly to customers.

The streaming service is currently only compatible on Sony-specific devices like the PS3, Blu-ray players, Sony Bravia TVs, and VAIO laptops. There are plans, says Sony, to offer it on mobile devices later this year.

Streaming Subscription Service (But Not for iOS)

These features of the new service all point to the current landscape of the music business - the increasing popularity of subscription services (such as MOG, Rhaposdy, and Rdio), for example, and the continuing struggles of the record industry to adapt to (declining) digital music sales.

But the launch of Music Unlimited also comes on the heels of Apple's announcement this week of its new subscription service, and the news that Apple would start to charge a 30% commission for purchases made within an iOS app. The news comes as Apple tries to gain more control over content bought and sold via apps on its platform, something that made Sony's proposed Reader app run afoul of the new rules and fail to be accepted into the store.

There were rumors earlier this week that Sony was planning on removing its music from iTunes in response to Apple, although Sony Network Entertainment COO Brandon insists that's not the case. Nonetheless, it's also noteworthy that Sony's new service isn't available on mobile devices - interesting since streaming-on-the-go is part of the benefits of streaming your music.